The recently discovered amber biota from Zhangpu, China, offers a unique window into the tropical ecosystem of an Asian rainforest during the Mid-Miocene Climatic Optimum (MMCO). Here, the first flat wasp (Bethylidae) from this deposit is documented: Parascle-roderma palaeosinica n. sp. is described and figured from a single male, and is the first fossil Parascleroderma known to date. The new extinct species is characterized by its minute size, the pedicel longer than the flagellomeres, the posterior ocelli inserted much posteriad on head, the notauli not impressed on anterior third of anteromesoscutum, and the hypopygium simple, with posterior margin slightly incurved medially. Parascleroderma is a cosmopolitan genus within the Pristocerinae and it is therefore not surprising to find its record in the Zhangpu biota, simultaneously with the northern expansion of the southeastern Asian tropical forest during the MMCO.(c) 2022 Elsevier B.V. and Nanjing Institute of Geology and Palaeontology, CAS. All rights reserved.